A high potassium level can occur if you have certain health conditions, including kidney disease or heart failure. But it can also have other causes, including certain medications and heavy alcohol use.
Potassium is an essential electrolyte, which is a mineral your body needs to function correctly. Potassium is especially important for your nerves and muscles, including your heart.
While potassium is important to your health, getting too much of the nutrient can be just as bad as — or worse than — not getting enough.
Normally, your kidneys keep a healthy balance of potassium by flushing excess potassium out of your body. But for many reasons, the level of potassium in your blood can get too high. This is called hyperkalemia, or high potassium.
According to the National Kidney Foundation, normal and high potassium levels, measured in millimoles per liter (mmol/L) of blood, are as follows:
- Normal: between 3.5 and 5.0
- High: from 5.1 to 6.0
- Dangerously high: over 6.0
A low potassium level can be determined with a blood test. Small variations in ranges may be possible depending on the laboratory.
Whether you have mild or severe hyperkalemia, you should get prompt medical attention to prevent possible complications.
Several things can cause hyperkalemia, including health problems and the use of certain medications.
Having kidney disease can raise your potassium levels because it damages your kidneys. They’re unable to remove extra potassium from your body, so it builds up in your blood.
- certain chemotherapy drugs
- angiotensin-converting enzyme (ACE) inhibitors
- angiotensin receptor blockers
Overuse of potassium supplements can increase your potassium levels to a range that’s higher than normal — or even dangerous.
Heavy alcohol use can cause your muscles to break down. This breakdown can release a high amount of potassium from your muscle cells into your bloodstream.
Certain kinds of trauma, like excessive burns, can raise your potassium levels. In these cases, extra potassium leaks from your body cells into your bloodstream.
Burns or crush injuries where a large number of muscle cells are injured can cause these effects.
Congestive heart failure
One possible cause may be the medications used for treating CHF, like angiotensin II receptor blockers, beta-blockers, and diuretics. These medications can interfere with the kidneys’ ability to excrete potassium.
HIV can damage your kidney’s filters so they’re less able to efficiently excrete potassium. Some common treatments for HIV, like sulfamethoxazole-trimethoprim therapy, are also associated with elevated potassium levels.
Other health conditions
High potassium can also be linked to certain health problems, like:
The symptoms of high potassium depend on the level of the mineral in your blood. You may not have any symptoms at all. But if your potassium levels are high enough to cause symptoms, you may have:
- tiredness or weakness
- a feeling of numbness or tingling
- nausea or vomiting
- trouble breathing
- chest pain
- palpitations or irregular heartbeats
In extreme cases, high potassium can cause paralysis.
Because the effects of high potassium can be serious, it’s important to address this condition right away.
Call your doctor right away if you have any of the symptoms above and you’ve been diagnosed with high potassium or have reason to think you have it. Call 911 or go to the nearest emergency room if your symptoms are severe.
If you have extremely high potassium levels, you’ll need to stay in the hospital until your levels return to normal.
You may want to ask your doctor some of the following questions:
- How much potassium is right for me?
- What could be causing my high potassium level?
- What changes should I make to my diet to lower this level?
- If I need medication, will there be any side effects?
- How often will I need follow-up blood tests?
A blood test can help your doctor diagnose hyperkalemia. Your doctor will routinely do blood tests during your annual checkup or if you’ve recently started a new medication. Any problems with your potassium levels will show up on these tests.
If you’re at risk of high potassium, it’s important to have regular checkups. This is because you may not be aware you have high potassium levels until you start developing symptoms.
The typical goal of treatment for high potassium levels is to help your body get rid of the excess potassium quickly and to stabilize your heart.
If you have high potassium due to kidney failure, hemodialysis is your best treatment option. Hemodialysis uses a machine to remove waste from your blood, including excess potassium, when your kidneys can’t filter your blood effectively.
Your doctor may also prescribe drugs to treat your high potassium levels. These may include:
Your doctor might first prescribe diuretics, which are pills that cause you to urinate more. Some diuretics increase the amount of potassium excreted by the kidneys, while others don’t increase potassium excretion.
Depending on your potassium level, your doctor might recommend one or more of the following types of diuretics:
- loop diuretics
- potassium-sparing diuretics
- thiazide diuretics
Each type of diuretic targets a different part of the kidneys.
In some cases, you may recieve a medication called a resin to take by mouth. Resin binds with potassium, allowing it to be removed from your body during your bowel movements.
Emergency medication treatments
As an urgent treatment to lower very high potassium levels, medications may need to be administered through an IV in a hospital.
Unlike diuretics and resin, these medications have only a temporary effect. They stabilize your potassium level and help reduce the effect it has on your heart.
These medications include:
If your high potassium is severe, you must get treatment right away. But if you have mild high potassium, you may be able to lower your potassium levels by making changes to your diet.
According to the National Kidney Foundation, a low-potassium diet can include up to 2,000 milligrams (mg) of potassium each day. Low-potassium foods generally contain 200 mg or less per serving.
Be sure to follow your doctor’s instructions for treating your high potassium, and talk with your doctor about the best diet plan for you. You can also ask for a referral to a dietitian or nutritionist.
Foods that are safe to eat
The following foods are low in potassium:
- fruits like apples, berries, cherries, and grapefruit
- vegetables including green beans, peas, eggplant, mushrooms, and kale
- protein sources like eggs, poultry, canned tuna, and beef
- cakes, cookies, and pies that don’t contain chocolate, nuts, or fruits high in potassium
Beverages with low potassium:
Foods to avoid
The following foods and beverages are high in potassium and should be avoided or eaten in moderation:
- fruits like bananas, avocados, oranges, and raisins
- vegetables including artichokes, brussels sprouts, potatoes, tomatoes, and tomato-based products like juice, sauce, and paste
- nuts, seeds, and peanut butter
- beans like baked beans, black beans, lentils, and legumes
- some herbs and herbal supplements, including alfalfa, coriander, nettle, and turmeric
- milk and yogurt
Some salt substitutes are also high in potassium. When you buy a salt substitute, make sure to avoid any that list potassium chloride as an ingredient.
Foods that are high in additives, like commercial baked goods and sports drinks, are also usually high in potassium.
If left untreated, high potassium levels can lead to the following complications:
To help prevent high potassium levels, you can do the following:
- Follow a low-potassium diet.
- Avoid salt substitutes.
- Avoid herbal supplements. Some may contain ingredients that increase your potassium levels.
- Follow your treatment plan. If you have heart disease, kidney disease, or another serious health condition, carefully stick to your healthcare professional’s treatment plan.
Because symptoms of high potassium may not appear in the early stage, you should get regular blood tests if you’re at risk for this condition.
If your blood tests show that you have high potassium levels, your doctor will choose the treatment plan that’s right for you.
If your levels are dangerously high, your doctor may prescribe hospitalization or dialysis. But suppose your potassium levels are slightly elevated and you don’t have any other symptoms of hyperkalemia. In that case, your doctor may choose to monitor your condition and order a follow-up test.
In either case, it’s possible to treat high potassium with prompt intervention.